Concrete-pole-forming process.



A. P. TAMM.

CONCRETE POLE FORMING PROCESS.

APPUCATION FILED DEC. 26. 1917.

1,262,863., Patented Apr. 16,1918.

INVENTOR.

Q 47% BY ATTORNEYS.

re carries,

ARTHUR 1?. TAMM, F MILWAUKEE, VIISCONSIN, KQSIGNOR 'IO UNIVERSE CONCRETE PRODUCTS COMPANY, OF CHICAGO, ILLINQIS, A GOBPORATIGN OF DELAWARE.

.CONCRETll-POLE-FOEMING PROCESS.

To all whom it may concern:

Be it known that I, ARTHUR P. TAMM, a citizen of the United States, and a resident of Milwaukee, in the county of Milwaukee and State of v iisconsin, have invented certain new and useful Improvements in Concrete-Pole-Forming Processes, of which the l the manufacture of concrete tubular pr ducts by the centrifugal process, a reinforcing structure is first placed in the mold and then concrete poured in in suliicient quantity to give the desired Wall thickness when the mold is rotated and centrifugal force becomes effective. It has been found that if the concrete at any part of the mold extends entirely across the mold, that is, closes the mold diametrally, the concrete will not separate at that point and distribute itsell to form a structure of uniform Wall surface when the mold is rotated.

Where the mold used comprises two semicircular halves and can be laid down during filling of one of the halves, such concentration and diametral filling of the mold cannot happen. However, Where the tubular mold is set on end or inclined during; charg- 4- is then applied and the mold raised'into in of concrete, and the mold then rought into horizontal position preparatory to being ins rted into a machine for axial rotation, the concrete at that end of the pole which was lowermost during filling will not always flow down and will diametrically entirely fill the mold that point, and then when the mold is rotated the concrete will not uniformly distributed and unequal wall thickness results. I have found that if, after filling of the mold and after return thereof to horizontal position, a passageway is forced through the concrete where it solidly fills the mold, the concrete Will then respond to centrifugal force andcwill distribute itself uniformly to form a wall of the desired uniform thickness. Such passageway or opening can readily be made in the concrete by the insertion of a bar or other suitable implement through the pole end and. the solid concrete. 1 am not certain just why the provision of such passageway or opening through the concrete results in uuiiorsn dis Specification of Letters Patent. Pietggfltgd App, 315 191%,

Application filed Deoemberfifi, 1937. Serial No. 208,954.

ltributionQ It may be that the suction at theend of'the pole due, to the compacting of the concrete at that end during filling prevents the concrete from assuming a common level during application of centrifugal force and that the forcing of a passageway through the solid sections of the concrete permits the entrance of air into and through the hole to break the suction effect, or it may be that a starting or priming opening is necessary before centrifugal action can become effective to distribute the concrete. It is not necessary that the passageway through the corn crete extend axially through the concrete as I have found that a passageway in any direction through the concrete'to break the solidity suiiiccs to cause uniform distribution of the concrete under centrifugal action.

On the accompanying drawing Figure 1 is a vertical diametral section oi? a mold with the concrete therein and show ing the application of a bar for forcing a passageway through the solid sections of the concrete, and

Fig. 2'shovvs a plug for closing the mold end during filling.

The mold 1 shown is cylindrical and slightly tapering and has the closure late 2 at one end provided with the threads openng 3 for receivingla plug 4. A suitable relnforcing structure 5 is inserted in the nu ld and alined by suitable spacers 6. The plug vertical position with its closed. end down or inclined-suliiciently so that concrete can be poured therein in quantities sulficient to form the desired Wall thickness when the mold is subjected to axial rotation and con trifugal force. After charging in of the concrete material the mold is restored to horizontal position preparatory to being in sorted in a machine or rotating it, but he fore rotation is started the plug 4: is removed and a suitable implement, such as the bar-K, is inserted through the opening 3 and through those sections of the concrete here the concrete solidly diametrally fills the mold. After filling the mold and returning it to horizontal position I find thatthe concrete at the closed end usually refuses to flow down and entirely closes the mold diametrally. It may he that at other parts of the mold the concrete likewise refuses to flow. However, by inserting the 7 a passageway is-made through these I l-W sections and then when the mold is rotated centrifugal action will become eilective and on account. of these passageways the. concrete will respond and will uniformly distribute itself and form Walls of uniform thickness. It is not necessary that the passageway through the solid concrete sections extend axially with reference to the mold as "i have found that no matter what the direction is so longas the passageway extends entirely through and a continuous air passageway is formed longitudinally through the mold, the concrete will readily respond at all points of the mold to centrifugal force.

Having described my improved process, I claim:

1. The process of manufacturing tubular concrete products which consists in inclining a tubular niold with its lower end closed, charging in concrete material in quantity sufiicient for the desired wall thickness then restoring the mold of the mold Where it extends entirely diametrally across and closes the mold, and then subjecting the mold to axial rotation and theconcrete to centrifugal force.

to horizontal position, then opening the end and forcing a passageway through the concrete at those sections 2" The process of manufacturing tubular concrete products,which consists in inclining a tubular mold with its lower end closed charging in concrete. in quantity sntlicient to produce the desired wall thickness when the concrete force, then inserting an implement through the mold end to force a passageway through the concrete and those sections of the mold Where the concrete extends entirely across and dianietrally fills the mold to therehy provide a passageway through such sections, and then axially rotating the" mold to subjectthe concrete to centrifugal action,

3. The process of filling-and preparing a concrete mold preparatory to subjecting it to axial rotation for the generation of centrifugal force which consists in pouring in the concrete and then inserting a suitable implement longitudinally v insure air passageway there'through from one end to the other before the mold is subjected to rotation.

in Witness whereof, my name this 20th day of December, 1917.

1 hereunto subscribe A. i).

is subjected to centrifugal into the mold to 

